The present invention relates to the heating and dividing into billets of logs of metal. Aluminium and alloys of aluminium are commonly cast into cylindrical bodies having a length of several meters and a diameter in the region of 150 to 200 mm. These bodies are called logs. Extrusion is commonly used to form aluminium and its alloys to useful shapes. A complete log cannot be accommodated in an extrusion press and it is therefore necessary to divide a log into several billets having respective lengths such that the billets can be charged, one at a time, into the breach of an extrusion press. The preferred length of a billet is dependant on the mass of the required extrusion. Some wastage of metal is unavoidable when converting a billet to a usable extrusion but it is desirable to minimise the mass of metal wasted, because of the energy needed to recycle wasted metal. It is therefore desirable for the logs to be divided into billets, the length of each billet being determined in accordance with the mass of the extrusion required to be produced from the billet.